JP2007108523A - Optical component module and camera module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical component module and a camera module, especially, the optical component module prevented from being damaged against shocks, given from the outside such as the dropping of equipment in which the camera module is mounted, even though the strength of a housing is lowered, because of the miniaturization, thinning and weight reduction of the camera module. <P>SOLUTION: The optical component module 2 is provided with at least a lens 6 being an optical component capable of moving in an optical axis 2a direction inside the housing 4 having aperture parts 15 and 16, and is provided with a main shaft 11 guiding the movement of the lens 6 in the optical axis 2a direction in the aperture parts 15 and 16. The optical component module 2 is provided with the main shaft 11, whereby a structure, capable of restraining the deformation of the housing 4, is obtained. If an imaging device is attached to the optical component module 2, the camera module can be formed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical component module capable of moving an optical component to be accommodated in an optical axis direction, and a camera module including such an optical component module and an image sensor.

  2. Description of the Related Art Conventionally, a compact camera, a digital camera, and the like are equipped with a camera module in which optical components and an image sensor are assembled in advance. Camera modules are not only compatible with high pixel counts such as millions of pixels, but are also becoming more sophisticated, such as auto focus adjustment and zooming mechanisms that enable wide-angle and telephoto zoom photography. .

  Generally, a camera module includes an optical system having a plurality of lenses and a substrate on which an image sensor is mounted. Furthermore, in a highly functional camera module, wide angle and telephoto shooting can be performed by changing the relative positions of lens holders each holding a plurality of lenses.

  On the other hand, in order to cope with the miniaturization and thinning of devices, there is an increasing demand for miniaturization, thinning, and weight reduction of camera modules. In response to this requirement, the lens system used for the optical system of the camera module has been reduced, and the housing of the camera module has been thinned. As a result, problems such as insufficient processing accuracy of the main body or damage to the camera module itself due to an impact applied to the camera module when the device falls are caused.

  For example, a lens is a typical optical component. A lens unit including a lens as an optical component is a box-type lens unit having an opening at one position above the lens optical axis and assembling an optical component such as a lens from the opening ( For example, see Patent Document 1). In this lens unit, a main body having an opening is formed by plastic molding.

  Since the optical component is incorporated into the main body, the optical performance is improved by the high-precision main body against the problem that the optical performance of the entire lens unit is deteriorated due to insufficient processing accuracy of the main body. More specifically, a concave groove extending in the optical axis direction is formed at the intersection of the walls in the box-type lens unit. Such a concave groove is provided in order to reduce deformation of the main body, and is presumed to reduce deformation due to a difference in cooling rate between the outer side and the inner side of the main body after molding.

  In addition, the lens is held on one end side of the optical axis of the optical system and a housing serving as the entire base is provided, and the two adjacent side surfaces and the shaft are erected from the housing in parallel with the optical axis. Also disclosed is a camera module for achieving the above (for example, see Patent Document 2). That is, the camera module disclosed in Patent Document 2 includes only a surface on which a front lens is mounted in a housing in order to reduce the size of the module, and two side surfaces parallel to the optical axis passing through the surface and the lens center. Is formed. Two shafts are provided adjacent to the side surface, and the shafts guide the sliding of the lens holder that holds the movable lens.

Japanese Patent Laid-Open No. 2002-14270 (FIG. 1) Japanese Patent Laying-Open No. 2005-195669 (FIG. 4)

  In the configuration disclosed in Patent Document 1, there is a problem that optimization is required regarding the structure such as the width, depth, and shape of the groove. In addition, when the housing is thinned, there is a problem that the strength of the groove portion is reduced. A guide shaft for guiding the movable lens group so as to move parallel to the optical axis is provided in the vicinity of the concave groove.

  In the configuration disclosed in Patent Literature 2, although the optical performance is not deteriorated due to deformation of the casing, only one of the shafts is fixed to the casing. As a result, the shaft vibrates when the lens holder slides, or the positional relationship is shifted from the optical axis, and the optical performance deteriorates, such as the lens holder coming off from the other unfixed shaft. There is a problem that there is a possibility.

  An object of the present invention is to provide a camera module, particularly a camera module against an impact applied from the outside due to a fall of a device on which the camera module is mounted, even if the strength of the housing is reduced due to downsizing, thinning, and weight reduction of the camera module. It is an object to provide an optical component module and a camera module that can prevent the optical component module from being damaged.

The present invention stores at least one optical component movable in the optical axis direction, and has a housing having an opening along the optical axis;
The optical component module includes a shaft provided to guide the movement of the optical component in the optical axis direction and provided in the opening.

  According to the present invention, the optical component module includes a housing and a shaft. The housing accommodates at least one optical component movable in the optical axis direction and has an opening along the optical axis, so that an assembly operation for housing the optical component in the housing can be performed from the opening. . The shaft guides the movement of the optical component in the optical axis direction and is provided in the opening, so that the rigidity of the opening can be increased and the strength reduction of the housing due to the opening can be compensated. Even if the strength of the housing is reduced due to the miniaturization, thinning, and weight reduction of camera modules including optical component modules, the optical component modules against impacts applied from the outside due to the fall of the device on which the optical component module is mounted. Can be prevented from being damaged.

In the present invention, the casing is substantially columnar extending in the optical axis direction,
The opening is provided on the columnar side surface.

  According to the present invention, the casing is formed in a columnar shape extending in the optical axis direction of the optical component, and the opening is provided on the columnar side surface. Therefore, the optical component movable in the optical axis direction in the casing is opened. Can be incorporated from

In the present invention, the casing is generally prismatic.
The opening is provided on at least two adjacent side surfaces.

  According to the present invention, since at least two adjacent side surfaces having a substantially prismatic shape are opened, there is no one side surface adjacent to the opening portion provided on one side surface, and the opening portion. When assembling the optical component into the inside of the casing, there is no interference from the side surfaces on both sides, and assembly adjustment becomes easy.

  In the present invention, the shaft is provided at a boundary portion between the two adjacent side surfaces.

  According to the present invention, it is possible to compensate for a decrease in strength due to the opening provided on two adjacent side surfaces by providing a shaft at the boundary.

In the present invention, a plurality of the shafts are provided.
According to the present invention, it is possible to more accurately guide an optical component that moves in a housing with a plurality of shafts in the optical axis direction and to reinforce the housing.

In the present invention, the casing is made of a unitary member.
According to the present invention, it is possible to reduce the size and weight by forming a casing with a single member and storing and holding optical components without requiring assembly work.

In the present invention, the casing is made of a flexible material.
According to the present invention, since the casing is made of a flexible material, it can be made difficult to be damaged even if it is deformed as necessary when an optical component is assembled. Since the optical component module is reinforced with a shaft, the processing accuracy can be maintained.

Furthermore, the present invention provides an optical component module according to any one of the above,
A camera module including an imaging device.

  According to the present invention, since the optical component module as described above is included, even if the strength of the housing is reduced due to downsizing, thinning, and weight reduction, it is applied from the outside due to dropping of the device on which the camera module is mounted. It is possible to prevent the camera module from being damaged by an impact.

  According to the present invention, at least one optical component movable in the optical axis direction is housed, and a casing having an opening along the optical axis can be enhanced and reinforced by the shaft provided in the opening. . It is possible to prevent the optical component module from being damaged by an impact applied from the outside due to a drop of a device on which a camera module including the optical component module is mounted.

  Further, according to the present invention, the casing is formed in a columnar shape extending in the optical axis direction of the optical component, and the opening is provided in the columnar side surface, so that the optical component movable in the optical axis direction in the casing is opened. It can be incorporated from the part.

  Further, according to the present invention, even when the housing is downsized, when assembling the optical component from the opening into the housing, there is no interference from the side surfaces on both sides, and assembly adjustment is facilitated.

  Moreover, according to this invention, the fall of the intensity | strength by providing an opening part in two adjacent side surfaces can be supplemented with the shaft provided in a boundary part.

  In addition, according to the present invention, it is possible to accurately guide an optical component in the optical axis direction with a plurality of shafts and to reinforce the casing.

  Further, according to the present invention, it is possible to reduce the size and weight by accommodating and holding the optical component without requiring the assembling work of the casing.

  Further, according to the present invention, the housing can be deformed as necessary when an optical component is incorporated. Since the optical component module is reinforced with a shaft, the processing accuracy can be maintained.

  Furthermore, according to the present invention, since the optical component module is provided in which the shaft shaft used for the movement of the optical component in the optical axis direction is provided in the region overlapping the opening of the housing, the deformation of the housing can be prevented. A highly rigid camera module can be obtained.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to FIG. FIG. 1 shows the overall configuration of a camera module 1 according to the present invention. FIG. 1A shows a simplified external configuration of the camera module 1, and FIG. 1B shows a schematic cross-sectional configuration of an optical system in the camera module 1.

  As shown in FIG. 1A, the camera module 1 detects an optical component module 2 having an optical system as shown in FIG. 1B and light processed by the optical component module 2. An imaging device 3. The optical component module 2 has a housing 4 shown in FIG. The housing 4 has a substantially columnar shape so that the optical axis 2 a as the optical component module 2 passes through the image sensor 3. The optical component module 2 shown in FIG. 1B has a configuration in which a lens group including a plurality of lenses 5, 6, and 7 is disposed in front of the optical axis 2a. Here, for the sake of simplicity, each of the lenses 5, 6, and 7 is shown as one lens, but each may be constituted by a plurality of lenses. Of the lens group, the lens 5 disposed in front of the optical axis 2 a and the lens 7 disposed immediately in front of the imaging device 3 are fixed lenses held by the housing 4. At least one lens 6 has a configuration capable of moving in the direction of the optical axis 2a. By moving the lens 6 in the direction of the optical axis 2a, it is possible to adopt a configuration in which the relative positions of the lenses 5, 6, and 7 of the optical system are optimized in accordance with zoom adjustment such as wide angle and telephoto. When the camera module 1 is built in a digital camera or a mobile phone, it is possible to shoot a landscape or the like under a wide range, close-up, or other conditions with different focal lengths by using a wide angle or telephoto.

  Next, members constituting the camera module 1 will be described. The sizes of the optical component module 2 and the image sensor 3 of the camera module 1 are restricted by the size of the electronic device on which the camera module 1 is mounted. In addition, the optical system provided in the optical component module 2 with respect to the image sensor 3 is configured to be optimal depending on the optical design.

  As the image pickup device 3, a light receiving pixel such as a CCD or a CMOS arranged in a one-dimensional linear shape or a two-dimensional surface shape is used. As the optical component module 2, not only the image sensor 3 but also a light receiving element such as a photodiode or a phototransistor can be used. Furthermore, light can be emitted from the lens 5 by using a light emitting element such as a light emitting diode (LED) or a laser diode to reverse the traveling direction of the light on the optical axis 2a.

  The lenses 5, 6 and 7 are made of an optically transparent material such as glass or plastic. Glass lenses are mainly machined out. A plastic lens is processed into a lens by molding using a mold. The shape is optimized by optical design when designing an optical system using a plurality of lenses 5, 6, and 7. Each lens 5, 6, 7 is formed as a spherical lens or an aspherical lens, and an edge is formed as necessary, and is housed and held in lens holders 8, 9, 10.

  When the optical component module 2 is an optical system that can perform zoom operation and automatic focus adjustment, the lens holder 9 is provided with a single lens or a plurality of lenses 6 to be subjected to zoom and automatic focus adjustment. Each lens mounted on the lens holder 9 is assembled and adjusted so as to suppress the eccentricity, and is fixed to the lens holder 9 with an adhesive or the like.

  Further, in order to slide the lens holder 9 along the optical axis 2a of the optical component module 2, the lens holder 9 is driven by a drive mechanism including a stepping motor and a cam, but the drive mechanism is not shown. The sliding of the lens holder 9 is guided along the shaft (the main shaft 11 and the sub shaft 12). The lens holder 9 is made of a resin such as ABS, polycarbonate, or liquid crystal polymer, and is formed by processing such as molding or cutting. As the resin used at this time, it is desirable to use a material having rigidity so that the shape is not deformed or damaged by a drop impact. The main shaft 11 and the sub shaft 12 are formed using iron-based metals including stainless steel, aluminum-based metals, copper-based metals including brass, and the like as materials. Not only solid rod-like materials but also hollow tubular materials can be used.

  The optical system described above is mounted on a housing 4 formed by processing such as molding or cutting using a resin such as ABS, polycarbonate, or liquid crystal polymer as a material to constitute the optical component module 2. The camera module 1 is composed of such a combination of the optical component module 4 and the image sensor 3.

  FIG. 2 shows the structure of the housing 4 shown in FIG. FIG. 2A shows the structure of the housing 4 provided with only one main shaft 11 and FIG. 2B shows the structure of the housing 4 provided with no shaft. The structure of the housing 4 is generally a columnar shape extending in the direction of the optical axis 2a, and end faces perpendicular to the optical axis 2a are used as lens holders 8 and 10 for fixing undriven lenses 5 and 7 in the optical system. The configuration to use is taken.

  More specifically, the housing 4 has a quadrangular prism shape, leaving two side surfaces 13 and 14 adjacent to each other among four side surfaces parallel to the optical axis 2a, and an opening 15 on the other side surface. , 16 is provided. The openings 15 and 16 may be part of the side surface instead of the whole side surface. As the camera module 1 is reduced in size and performance, if there is only one opening, when the optical system is incorporated into the housing 4, the left and right sides of the opening interfere with each other, making assembly adjustment difficult. And the problem that it is difficult to handle optical components. However, if the structure has no opening and two adjacent surfaces, a space for assembling and adjusting the optical system can be obtained, and an optical system of the camera module 1 with high accuracy can be formed. In addition, although the structure which removed two side surfaces was demonstrated here, three adjacent side surfaces can also be removed and it can also be set as an opening part, respectively.

  In order to process such a casing 4, methods such as molding and cutting as described above can be used. In particular, when the casing 4 is formed by molding, the mold can be divided in a plane perpendicular to the optical axis 2a, the molds on both sides are combined, the resin material is filled into the internal cavity, and then the mold is A method of removing them separately is common. When molded by such a method, as shown in FIG. 2 (b), some regions of the housing 4 that do not have a surface parallel to the optical axis 2a, such as the lens holders 8 and 10, are deformed. There is. When such deformation occurs, if the lens holders 8 and 10 hold the lenses 5 and 7, respectively, the lenses 5 and 7 are inclined with respect to the optical axis 2a. The optical performance will be reduced.

  For example, the lenses 5, 6 and 7 are ordered along the optical axis 2a, and the lens holders 8 and 10 to which the first lens 5 and the third lens 7 are attached are as shown in FIG. Consider the point that becomes a problem when tilting to the inside of 4. As described above, since the first lens 5 and the third lens 7 attached to the lens holders 8 and 10 of the housing 4 are inclined with respect to the optical axis 2a, the optical performance of the optical system is deteriorated. . In addition, since the relative positional relationship between the first lens 5 and the third lens 7 changes in the direction of the optical axis 2a, a new optimum is obtained by moving the lens holder 9 in order to obtain an optimum relationship with the image sensor 3. In addition, there is a possibility that an optimal positional relationship cannot be obtained even if the robot moves.

  For example, assuming that the size of the housing 4 of the optical component module 2 is 30 mm square and the inclination of the lens holder 8 on one end side of the housing 4 is about 5 minutes, the first lens 5 has the optical axis 2a. A positional shift of about 20 μm will occur in the direction. The light beam incident on the center of the lens travels on the optical axis of the inclined first lens 5 and passes through a position deviated from the optical axis 2 a by about 40 μm at the position of the lens holder 10 on the other end side of the housing 4. It will be. Such a change of several tens of μm greatly affects the optical performance together with a manufacturing error and an error in assembly adjustment as the camera module 1 is downsized.

  Furthermore, since the inclination of the lens holder 8 on one end side of the housing 4 also causes the shaft hole 17 that penetrates the shaft 11 to be inclined, the shaft 11 may be fixed while being inclined with respect to the optical axis 2a. Can be considered. As a result, the second lens 6 held by the lens holder 9 that moves with the shaft 11 as a guide axis also moves in an inclined state with respect to the optical axis 2a, which further causes a decrease in optical performance. It will end up.

  As a method for suppressing a decrease in optical performance, the shape of the housing 4 such as the lens holder 8 on one end side and the lens holder 10 on the other end side is determined in consideration of deformation of the housing 4 due to processing, or the shaft hole What is necessary is just to take measures, such as making 17 the shape which becomes parallel to the optical axis 2a after the deformation | transformation of the housing | casing 4. FIG. However, such a measure is an empirical rule obtained by several trial productions, and there is a problem that manufacturing variation increases because it is greatly affected by conditions during processing.

  Further, not only the problem with respect to the deterioration of the optical performance described above, but also with such a configuration in which the side surface is opened, the rigidity of the housing 4 becomes weak, and even when the camera module 1 is used, the electronic device is dropped. The problem that it becomes easy to damage will arise.

  Therefore, as shown in FIG. 2 (a), the shaft 11 is provided in a region (corner) where the side surfaces 13 and 14 do not exist, and the side surfaces overlap each other. As a method for fixing the shaft 11, there is a method in which a shaft hole 17 is provided, the shaft 11 is press-fitted in a required length from the shaft hole 17, and then fixed by heat caulking or the like. Moreover, since the housing | casing 4 is formed from the resin material which has flexibility, there exists the method of inserting the shaft 11 from the side surface opened using the deformation | transformation of the housing | casing 4. According to the configuration in which the shaft 11 is provided in this manner, the length of the shaft 11 is made the same as that of the side surface of the housing 4, thereby suppressing the deformation of the structure of the lens holders 8 and 10 at both ends in the axis 2 a direction of the housing 4. In addition, since the first lens 5 and the third lens 7 and the optical axis 2a can be in a perpendicular relationship, it is possible to prevent performance degradation of the optical system. Here, the shaft 11 is the main shaft 11 that serves as a reference axis for guiding the moving lens holder 9, but it may be a shaft 12 that serves as an auxiliary shaft as shown in FIG.

  FIG. 3 shows an effect that the shaft 11 can increase the rigidity of the region without the housing 4. FIG. 3A shows a configuration in which the shaft 11 is not provided, and FIG. 3B shows a configuration in which the shaft 11 is provided. Even if the lens holders 8 and 10 at both ends in the direction of the axis 2a of the housing 4 have sufficient rigidity, if the shaft 11 is not provided as shown in FIG. The portions of the side surfaces 13 and 14 of the casing 4 to be connected are deformed, and the optical performance is lowered similarly to the deformation of the lens holders 8 and 10 as shown in FIG.

  As described above, by reinforcing the optical component module 2 with the shafts 11 and 12, the camera module 1 that does not affect the drop impact of the electronic device can be obtained. Further, since the tilt of the optical system is unlikely to occur, even when a combination lens is used as an optical component to improve coma aberration, astigmatism, etc., an increase in aberration due to deformation of the housing 4 is prevented. be able to. The shape of the housing 4 is not limited to the shape of a quadrangular prism, and the present invention is not limited as long as the number of corners is different or the side surface is a curved surface so long as the opening is provided. Applied, the opening can be reinforced with a shaft.

1 is a perspective view showing an external configuration of a camera module 1 according to an embodiment of the present invention, and a cross-sectional view showing a schematic configuration of an optical system. FIG. 2 is a schematic perspective view showing the structure of the housing 4 of FIG. 1 in comparison with the presence or absence of a shaft 11. FIG. 2 is a schematic cross-sectional view showing the structure of the housing 4 of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Camera module 2 Optical component module 2a Optical axis 3 Image pick-up element 4 Case 5 1st lens 6 2nd lens 7 3rd lens 8, 9, 10 Lens holder 11 Main shaft shaft 12 Sub shaft shaft 15,16 Opening part

Claims (8)

Housing at least one optical component movable in the optical axis direction and having an opening along the optical axis;
An optical component module comprising: a shaft provided to guide the movement of the optical component in the optical axis direction and provided in the opening. The housing is substantially columnar extending in the optical axis direction,
The optical part module according to claim 1, wherein the opening is provided on the columnar side surface. The housing is generally prismatic,
3. The optical component module according to claim 1, wherein the opening is provided on at least two adjacent side surfaces.   The optical component module according to claim 3, wherein the shaft is provided at a boundary portion between the two adjacent side surfaces.   The optical component module according to claim 1, wherein a plurality of the shafts are provided.   The optical component module according to claim 1, wherein the casing is made of a single member.   The optical component module according to claim 6, wherein the casing is made of a flexible material. The optical component module according to any one of claims 1 to 7,
A camera module comprising an imaging device.

Images